10. [0.09/0.27 Points] DETAILS PREVIOUS ANSWERS BBUNDERSTAT12 7.4.022. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER "Unknown cultural affiliations and loss of identity at high elevations." These are words used to propose the hypothesis that archaeological sites tend to lose their identity as altitude extremes are reached. This idea is based on the notion that prehistoric people tended not to take trade wares to temporary settings and/or isolated areas. As elevation zones of prehistoric people (in what is now the state of New Mexico) increased, there seemed to be a loss of artifact identification. Consider the following information. Elevation Zone 7000-7500 ft Number of Artifacts 5000-5500 ft 115 Number Unidentified 69 137 23 Let p1 be the population proportion of unidentified archaeological artifacts at the elevation zone 7000-7500 feet in the given archaeological area. Let p2 be the population proportion of unidentified archaeological artifacts at the elevation zone 5000-5500 feet in the given archaeological area. (a) Find a 95% confidence interval for p1 - p2. (Use 3 decimal places.) lower limit upper limit9. [0.09/0.27 Points] DETAILS PREVIOUS ANSWERS BBUNDERSTAT12 7.4.021. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER On the Navajo Reservation, a random sample of 210 permanent dwellings in the Fort Defiance region showed that 64 were traditional Navajo hogans. In the Indian Wells region, a random sample of 153 permanent dwellings showed that 23 were traditional hogans. Let p, be the population proportion of all traditional hogans in the Fort Defiance region, and let p2 be the population proportion of all traditional hogans in the Indian Wells region. (a) Find a 99% confidence interval for p1 - p2. (Use 3 decimal places.) lower limit upper limit8. [0.09/0.27 Points] DETAILS PREVIOUS ANSWERS BBUNDERSTAT12 7.4.020. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER A study of parental empathy for sensitivity cues and baby temperament (higher scores mean more empathy) was performed. Let x1 be a random variable that represents the score of a mother on an empathy test (as regards her baby). Let X2 be the empathy score of a father. A random sample of 30 mothers gave a sample mean of x1 = 68.19. Another random sample of 32 fathers gave X2 = 61.21. Assume that Of = 10.99 and 02 = 11.13. (a) Let M1 be the population mean of x1 and let U2 be the population mean of X2. Find a 99% confidence interval for M1 - M2. (Use 2 decimal places.) lower limit upper limit7. [0.09f0.27 Points] BBUNDERSTAT127.4.019. The US. Geological Survey compiled historical data about Old Faithful Geyser (Yellowstone National Park) from 1870 to 1987. Let X1 be a random variable that represents the time interval (in minutes) between Old Faithful eruptions for the years 1948 to 1952. Based on 9760 observations, the sample mean interval was x1 = 63.4 minutes. Let X2 be a random variable that represents the time interval in minutes between Old Faithful eruptions for the years 1983 to 1987. Based on 24,053 observations, the sample mean time interval was x2 = 71.2 minutes. Historical data suggest that 0'1 = 9.33 minutes and 0'2 = 11.57 minutes. Let [.11 be the population mean of x1 and let #2 be the population mean of x2. (a) Compute a 95% condence interval for [.11 - [.12. (Use 2 decimal places.) lower limit upper limit 6. [0.091027 Points] DETAILS PREVIOUS ANSWERS BBUNDERSTAHZ 7.4.013. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER Most married couples have two or three personality preferences in common. A random sample of 374 married couples found that 130 had three preferences in common. Another random sample of 578 couples showed that 222 had two personality preferences in common. Let p1 be the population proportion of all married couples who have three personality preferences in common. Let p2 be the population proportion of all married couples who have two personality preferences in common. (a) Find a 99% condence interval for p1 - p2. (Use 3 decimal places.) lower llmitl l upper limit 5. [0.09I0.27 Points] BBUNDERSTAT127.4.017. A random sample of 366 married couples found that 300 had two or more personality preferences in common. In another random sample of 568 married couples, it was found that only 40 had no preferences in common. Let p1 be the population proportion of all married couples who have two or more personality preferences in common. Let p2 be the population proportion of all married couples who have no personality preferences in common. (a) Find a 90% condence interval for p1 - p2. (Use 3 decimal places.) lower limit l l upper limit I I 4. [0.091027 Points] BBUNDERSTAT12 7.4.014. Independent random samples of professional football and basketball players gave the following information. Assume that the weight distributions are mound-shaped and symmetric. Weights (in lb) of pro football players: x1; n1 = 21 243 253 254 251 244 225 240 265 25? 252 282 256 250 264 2'20 225 245 225 253 265 23"2 Weights (in lb) of pro basketball players: x2; n2 = 19 204 200 220 210 191 215 223 216 228 20? 225 208 195 191 20? 196 181 193 201 (a) Use a calculator with mean and standard deviation keys to calculate X1, 31, X2, and 32. (Round your answers to one decimal place.) 31: 51: 32: 52: (b) Let [.11 be the population mean for x1 and let #2 be the population mean for X2. Find a 99% condence interval for [11 - 112. (Round your answers to one decimal place.) lower limit upper limit 3. [0.091037 Points] DETAILS PREVIOUS ANSWERS BBUNDERSTAT12 7.4.013. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER For large U.S. companies, what percentage of their total income comes from foreign sales? A random sample of technology companies (IBM, Hewlett-Packard, Intel, and others) gave the following information.t Technology companies, 95 foreign revenue: :1: n1 3 16 62.8 55.? 47.0 59.6 55.3 41.0 65.1 51.1 53.4 50.8 48.5 44.6 49.4 61.2 39.3 41.8 Another independent random sample of basic consumer product companies (Goodyear, Sarah Lee, H.J. Heinz, Toys 'R' Us) gave the following information. Basic consumer product companies} foreign revenue: 13:11; I 17 28.0 30.5 34.2 50.3 11.1 28.8 40.0 44.9 40.7 60.1 23.1 21.3 42.8 18.0 36.9 28.0 32.5 Assume that the distributions of percentage foreign revenue are mound-shaped and symmetric for these two company types. (a) Use a calculator with mean and standard deviation keys to calculate x1, 31, X2, and 32. (Round your answers to two decimal places.) It= I96 81 '96 52 |% 52 |% (b) Let 1.11 be the population mean for x1 and let [.12 be the population mean for x2. Find a 99% condence interval for [11 - 1.12. (Round your answers to two decimal places.) Iowerlimit |% upper limit |% 2. [0.09/0.27 Points] DETAILS PREVIOUS ANSWERS BBUNDERSTAT12 7.4.012. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER Inorganic phosphorous is a naturally occurring element in all plants and animals, with concentrations increasing progressively up the food chain (fruit